P2557
Engine Coolant Level Sensor/Switch Circuit Range/Performance
What it means
The coolant level sensor is electrically intact, but the readings are implausible — for example a level that does not move at all over many drive cycles, or jumps that cannot match real coolant loss. Often a stuck float, contaminated electrode or air-locked sensor.
Is it safe to drive?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Stuck float
highOne of the most commonly reported causes for this code — check this first.
Trapped air around the sensor
mediumA plausible cause — test and verify before replacing parts.
Sensor element aged beyond calibration window
lowLess common, but worth ruling out after the more likely causes.
Related help
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